Heart of the Sea
by themusicain
Summary: The TARDIS lands in the city of Atlantis. However, there's something wrong with the city's power source. Follows on after my "The Unearthly Child"
1. Prologue

Prologue

Prologue

Kaelah started the fire, watched it fizzle out, and tried again. And again.

It wasn't the damp that was doing it. Atlantis had always been rather damp, but that had never stopped a fire lighting before. She sighed softly, her gills moving as she did so. Plenty of air in the vicinity, so _that_ wasn't causing the fire to go out either. So what was it?

Doubts and worries began to creep into her mind, but she pushed them back, just as she would if her long white hair got into her sea-green eyes. Something told her she should report this problem to the senate, but she was reluctant; who would listen to a sixteen-year-old girl?

She sighed and tried again.

At first she thought she'd succeeded, but the flame that shot up from the wood was clear, not yellow. And it was growing much faster than normal fire. Kaelah backed away, thinking that perhaps she should report this after all.

_Bad idea_, said a voice from somewhere. She spun round, but there was no one else in the garden. The seaweed patches were too thin for someone to hide there, and she'd see if someone were in the pool.

_I'm over he-ere_, said the voice tauntingly. She turned back to the fire and was startled to see that it was as high as she was sitting. What's more, it had formed a face; she could see the garden behind it bent into the contours of a mouth, eyes and nose. She tried to yell out, but her voice had stopped working. _Perfect_, said the face, and rose to engulf her, forcing its was through her eyes, nose, ears, gills and mouth.


	2. Chapter 1

Chapter 1

Donna had almost got used to the fact that the teenager standing beside her was actually a sixty-year-old widow. Almost. What made it harder to believe was that she was also the granddaughter of the young man standing at the control console. _Who is actually an alien_, she reminded herself. But she'd learnt to expect the unexpected with the Doctor, so the initial shock had worn off pretty quickly.

"Where are we going, Martian Boy?" she asked the Doctor.

Shooting her a withering look, he shrugged. "I'm about to put the TARDIS onto "shuffle"," he said.

"What, like an MP3 player?"

He flashed her a trademark grin. "_Exactly_ like an MP3 player."

She girl beside Donna snorted softly. She'd plaited her long brown hair into two long ropes that hung down her back. Despite the Doctor complaining that Susan should get her hair cut, she'd flatly refused.

Donna would never forget the morning the Doctor came to pick her up after a night away from time travelling and world-saving at her parents' house, and introduced her to his sixty-year-old granddaughter.

She wasn't sure what she'd have expected from a descendent of the Doctor. Certainly, Susan was very clever, but she actually tried to make things understandable; she'd become a sort of unofficial translator of the Doctor. She also had a confident air of independence, which Donna had taken an instant liking to.

A sudden rocking of the TARDIS floor jerked Donna out of her thoughts and off her feet.

"That the play button you've just pressed, then?" she yelled, staggering, reaching out for the railing around the console. The part of her not concentrating on maintaining her balance noted that the Doctor had one leg wrapped round the console, his foot pressing a lever that looked suspiciously like a bottle top, whilst one hand was whacking a set of buttons with a small hammer. He nodded, his sonic screwdriver between his teeth.

With a last whine of the TARDIS engines, the floor stopped moving and the passengers were able to stand unaided. As things quietened again, they became aware of music playing.

"That's _Neptune_," said Susan.

"Neptune?"

"From _The Planets_ by Gustav Holst," she explained. "I played it with a youth orchestra last year."

"Are we on the planet Neptune?" asked Donna excitedly.

The Doctor shrugged again. "Might be. Go take a look."

Donna had heard all about the protective shield around the TARDIS when she'd first met the Timelord, and knew they'd be safe so long as they stayed inside the TARDIS. Nevertheless, she was still apprehensive about going out onto a gas planet. "Why don't you go first, Susan?"

With a wink, Susan walked to the door, which the Doctor opened by pressing a button that looked rather like a bottle top. Then she fell forwards as her foot snagged on a loose cable, and fell out of the TARDIS with a squawk and a splash.

A _splash_?

The Doctor and Donna ran to the door, to see that the TARDIS was parked on the edge of a large pool. They were just in time to see Susan emerge with a splutter, only to be dragged back down again with a yell. Donna yelled too when she saw the Doctor dive in after her. At the same time, she saw a blue figure leap in at the other side of the pool.

The minute he saw his granddaughter get pulled under, the Doctor had pulled off his jacket and shoes and plunged in after her. Despite the fact that he knew her lungs were bigger than the average humans- due to her Timelord genes- he wasn't sure how big they were. Hell, he hadn't even bothered to check if she had a second heart!

He peered through the water, and saw Susan getting pulled even deeper by a grey shape that looked oddly familiar.

A blue shape arrowed towards the grey one and prodded it. Abruptly, it let go of Susan, and she was pulled to the surface by the blue figure. The Doctor kicked his legs and followed.

When he surfaced, he saw Donna standing in the TARDIS doorway, her mouth hanging open, staring at the other side of the pool. Turning his head, he saw the blue figure leaning over Susan, who appeared to be coughing up large volumes of water. He swam over.

The blue figure looked up at him with bright green eyes. The shape of his body and the short white hair told the Doctor that he was male. His blue skin was wet, and the Doctor was sure he could see gills flapping on his neck. The blue person raised webbed hands in a gesture of reassurance.

"She's okay, I think. I don't know why she's coughing up water, though. Does she have gill problems?"

"No," replied the Doctor, hauling himself out of the pool. "She doesn't have any at all. We're not from around here, you see." He bent anxiously over Susan.

"Oh? In that case, I should be saying, "Welcome to Atlantis." My name is Jalem."

The Doctor cracked such a huge grin so suddenly, Jalem stepped back a bit, alarmed.

"Atlantis! Oh, I've always wanted to come here!" He grew serious again. "What was that thing in the water?"

"My dolphin, Petra," said Jalem, blushing. This caused his face to go an interesting shade of purple. "She must have thought it was me; that's how she always greets me. I'm sorry, she won't do it again." Jalem looked a little worried now.

The Doctor smiled again and turned to face where Donna was still staring at them.

"Come on in, Donna, the water's fine!"


	3. Chapter 2

Chapter 2

Jalem insisted that the Doctor, Susan and Donna met the Atlantean Elders. The Doctor needed little persuasion. Still dripping wet, they followed Jalem out of what looked rather like a park of some sort, and up a long, wide, cobbled road. Except, when Donna looked closer, she saw that it was shells, not stones, on the road.

Everything around them had a blue-ish tinge, and there was water everywhere: it cascaded in waterfalls from the roofs of the small houses, flowed in streams along the street, glistened serenely in pools, and trickled out of statues in fountains. Blue-skinned Atlanteans stopped and stared at the pink-coloured beings walking in their midst. The Doctor grinned and waved enthusiastically, Donna blushed and smiled at their interest, and Susan simply stared back, but in a way that suggested she was examining the area closely. _There certainly is a lot to see_, thought Donna.

They were led to a huge palace, and Jalem explained that this was a public building, since the last ruler had died with no heir. There were hints of Greece and Ancient Egypt in the architecture, but it was still unlike anything that Donna had ever seen. _Over a year ago_, she thought, _I was going to go to Greece for a honeymoon with a husband. Not much chance of that happening now, of course. But it makes me think; knowing me, I'd have just sat on a beach or in a restaurant. I probably wouldn't even have _thought _of going to see some ruins._ It was moments like this that made her realise just how much the Doctor had changed not only her life, but her as well.

Two guards stood outside a huge open doorway, which led to a large hall. The inside had been shaped to look like the inside of an enormous shell, and even more pools and waterfalls glistened on the walls and the floor. Seated around the largest of these were three men and two women. All had the same blue skin and white hair as Jalem, and Donna suspected their eyes would be just as green. They rose to greet the threesome.

"Welcome to Atlantis," said the one in the centre, a youngish looking man.

"Thank you," replied the Doctor with another grin, and held out his hand. The Atlantean looked at it oddly then turned to Donna and Susan, who was trying to suppress a smirk.

"May I ask your names?"

"My name is Susan Campbell," said the still-wet Susan. "This is my grandfather, the Doctor, and our friend, Donna Noble. And you are…?"

"I am Heram, this is Jerom, Ylea, Sani and Forem. What are you?"

"We're Time Travellers," said the Doctor.

"That doesn't explain your strange colouring," said the older woman, Ylea, with a stern expression. _Uh oh_, thought Donna. _This one could make things a little difficult. And, of course, the Doctor's gonna try and charm her too_.

"I'm human, " began Donna, but was interrupted by an outraged hiss. A young woman rushed at her.

Quick as a flash, the guards grabbed her and held her down. Jalem to her side.

"Kaelah!"

The Doctor followed him and knelt down by the thrashing girl. He pressed the back of her neck, and she went limp.

"Just like a Vulcan!" muttered Donna.

"Nice enough guys, if a bit formal and distant," said the Doctor. "Now then," he went on, turning back to face the girl. Jalem was crouching beside her now, holding her webbed hand in his, staring at her with a worried expression.

"What did you do to her?" he asked, fear in his voice.

"Calmed her down, that's all. What did you say her name was?"

"Kaelah," he replied.

"Okay then… hello Kaelah…" the Doctor reached out for Kaelah's temples and closed his eyes.

"What's he doing?" whispered Donna.

"Looking into her mind, I think," replied Susan. She turned to her companion. "Wonder what she's got against humans, then."

"They abandoned us," said a deep voice behind them.

They turned to see the oldest member of the council, Jerom.

"Excuse me?"

"When Atlantis sank, the humans left us to our fate. We were once like you" –he pointed at Susan and Donna- "but we were forced to… adapt."

"There was no way the humans could have saved you," Susan pointed out. "They had no way of reaching you." Jerom shook his head.

"_You_ came here."

"Our technology's rather more advanced than the humans' back then. Besides, I'm not exactly human."

"Not human?"

"Half-human. My father was a Time Lord, like the Doctor."

_Timelord!_

Everyone spun round to find the source of the voice, but no one could find the speaker.

On the floor, the Doctor had finished his mind reading, or whatever he'd been doing, and was helping Kaelah to sit up. Jalem still held her hand, and was rubbing her back gently. She looked confused.

"Whuh… what happened?"

"You tried to attack our guests," said Ylea, rather coldly, Donna thought.

"I did?" Kaelah looked shocked now. "The last thing I remember, I was in the gardens-"

"I was there fifteen minutes ago," interrupted Jalem, helping her to her feet. "I didn't see you."

The younger woman, Sani, looked at her, concerned. "Get some rest," she said softly. Kaelah nodded, and allowed Jalem to lead her away.

The Doctor clapped his hands together and winked at his companions.

"I smell something fishy."


	4. Chapter 3

Chapter 3

The threesome were shown into two immaculate washrooms and showered with towels and dry clothes. Half an hour later, Susan and Donna emerged, dry and dressed in typical Atlantean tunics, to be told that the Doctor was already dry, and was waiting for them in the banquet room.

They entered a huge hall, adorned with the biggest shells they'd ever seen, and, yet again, full of waterfalls. The Doctor was still in his suit- though he appeared to have dried it- and was deep in conversation with the oldest member of the council, Jerom. Susan sat beside him with Donna on her other side.

Everyone was very quiet during the decidedly fishy meal. Afterwards, however, conversations began the second the last plate had been taken away. The hot topic of the evening was the Doctor and his companions.

"So, you say you are Time Travellers, yes?" asked Jerom.

"Yup. And we're absolutely fascinated by your beautiful city."

The stern one, Ylea, gave him a tight smile.

"Thank you. But, as you can see, we are a city with a mystery, and not a pleasant one at that."

"Ah, they're all like that," said the Doctor in what was obviously meant to be a reassuring tone.

"What I think Ylea means, is that there is something going on in Atlantis. Something _wrong_." Ylea nodded her agreement.

"Then let us help you," said Susan. "We often end up solving mysteries. Occupational hazard of Time Travel."

"We'll take you up on your offer," smiled Sani, the younger woman. She turned to the Doctor. "What was that that you did to Kaelah?"

"Just a little trick I learnt years ago," replied the Doctor modestly.

"What did you see?" asked Susan, who knew a thing or two about the Doctor's "little trick" herself.

"I can confirm that _her_ last conscious memory was indeed trying to light a fire in the garden. I tried to access what happened between then and her attack in the council chamber, but- nothing!" He shook his head. "Normally, the eyes register images even if the brain doesn't, and with a little persuasion, I can get at these. But I didn't find anything at all! It's as if someone had put a dead-lock seal on, or forgotten to file it, or… or scrubbed the retinas."

There was a pause while everyone processed this information. Susan had noticed the emphasis he'd put on the word "her" when he talked about "_her_ memories," and she didn't like the implications of this at all. "Perhaps we could go check out the garden," she suggested.

"Can we do that tomorrow?" asked Donna suddenly with a yawn. "I'm so tired… and I don't feel so good…"

"Sure, we'll do that tomorrow," said Susan quickly, her eyes daring the Doctor to argue. He did anyway.

"Why not now?" he pouted.

"We're knackered, and Donna's not feeling well."

"Speak for yourself."

"No one said you had to go to bed! You can stay up if you want to!" Susan was trying very hard not to laugh. The grandfather she remembered was very different from the grandfather she had now. It was almost as if she was _his_ grandmother!

"We'd be happy to supply the ladies with bedrooms and medicine," said the fifth member of the council, Forem.

"Thank you," said Susan.

"But hold the medicine," said Donna, standing up slowly. "I'll just sleep it off, thanks."

They were to share a bedroom. Like all the rooms they'd been in, it was large and luxurious. The two women climbed into bed eagerly. Donna fell asleep almost immediately.

Susan examined her closely. Donna's face was pale, and her forehead very warm. The heat on her palm reminded Susan of days spent at home with a daughter full of the 'flu, a son sick with a stomach bug…

She wiped her eyes on her sleeve and slid under the covers. Her thoughts moved to her late family, and she fell asleep thinking of happy times…

DW

The lighting, the Doctor noticed, was not candlelight, but a cold, blue light. It reminded him a little of his sonic screwdriver. The thought was strangely comforting.

"What's in the lights?" he asked Sani, who had stayed in the banquet room with him.

"A small sliver of crystal," she replied. "The crystals are collected from the river that runs through the city."

"Natural phosphorescence?"

"Err… what?"

"They glow on their own?"

"Oh. No." She smiled. "They're powered by the Heart of the Sea, our power source. It protects Atlantis and her inhabitants, provides us with light and power, enables us to light fires where it would otherwise be too damp, and occasionally heals injuries that are beyond our healing abilities."

"Sounds amazing," murmured the Doctor. "Ever seen it?"

"No. No one knows where it is."

_Sounds like a challenge_, thought the Doctor.

DW

Susan woke from dreams of falling down ravines. At first, she thought it was the fear of the nightmare that had woken her, but she became aware of a feeling… that something was not right… She couldn't explain what it was. It was like the instinct that told her a child had woken and was at that very moment padding down the corridor in search of a consoling hug.

She sat up and glanced around the room. Donna was still asleep. Only the faintest glow was emanating from the light in the middle of the room, like a dim star. But still the feeling remained. Then she heard a noise, like water trickling. But there was water everywhere in Atlantis, that was to be expected. Then she thought she caught sight or a reflection of water on the floor, reflecting the dim light of the crystal. But when she looked closer, there was nothing…

DW

The lights flickered. The Doctor glanced upwards, then at Sani, noticing her worried frown.

"I suppose this isn't normal?"

"No. The lights have never flickered before. This is what Ylea meant when she said there was something wrong."

"Like when I said Kaelah was _trying_ to light a fire? You looked a little concerned then too."

"It should have lit the first-"

A scream echoed down the hallway.

The Doctor dashed out of the room, Sani close at his heels.

Bursting into Susan and Donna's room, he saw Susan sitting up groggily. Sani blew on the light, and the room grew brighter.

"Wha' you doin' h-h-h-here?" Susan yawned widely. The Doctor and Sani exchanged glances.

"I heard a scream…" At once, the Doctor could tell something was wrong here. Susan would never have slept through a noise like that, not as a mother of three kids. And Donna was still asleep.

"Susan, would you mind awfully if I went into your mind for a moment?"

"Why?" asked a rather suspicious Susan.

"I just want to check something… I can't get in unless you let me, you know that."

"You did with Kaelah," muttered Sani.

"Kaelah was unconscious, and Susan knows how to keep people out of her mind." He reached out for Susan's temples and closed his eyes, just as he had with Kaelah. Susan's mind was easier to get into; he knew her well, and he had her permission- as opposed to that memorable time when he found her again after forty-five years, where he had definitely _not_ been invited- but he still sensed confusion from her mind. She didn't think there was anything wrong. He went through her recent memories, from falling out of the TARDIS to falling asleep… then waking up to the sounds of the Doctor bursting in.

_Is my hair really that messy?_ he thought absently as he pulled away. He wasn't sure, but he felt there was something missing. And why was Donna still asleep? Surely he'd made enough noise to wake her up by now?

"Find anything?"

"Nope, seems all present and correct." Susan could hear the doubt in his voice.

"We could check with the TARDIS tomorrow."

The Doctor nodded, turning to look at the sleeping Donna, and feeling her forehead.

"Since she's _ill_, I think I'd better take a _blood-sample_ and see what's _wrong_ with her," he said slowly.

Susan caught what he was implying, and looked at Donna anxiously. Sani coughed.

"If you don't mind, Doctor, I think I'll say goodnight. See you in the morning."

The Doctor nodded once, and proceeded to take a sample of Donna's blood. Donna didn't stir at all. Giving her a last concerned glance, he kissed Susan on the cheek and left the bedroom, pausing only to check his reflection in a mirror, and to attempt to flatten his hair.

The light dimmed as Susan blew on it. She curled up under her covers, and resumed her interrupted sleep.

DW

_Power fading. Need more Power. But where to get Power from? Power has been brought within my reach. Power shall be gained. Power shall be restored._


	5. Chapter 4

Chapter Four

Jalem made his way over to the male servants' quarters. He and Kaelah had recently started work at the palace, and loved every minute of it. But now he wanted to get away. He couldn't say why, apart from that he could tell there was something wrong in Atlantis.

He'd taken Kaelah back to her room. He hated to leave her there on her own, but one of the other ladies had assured him she'd keep an eye on her. He kicked at a loose shell gloomily and watched it skitter into a nearby pool.

The servants' quarters were two long, low buildings, plain but comfortable. Jalem thought this was way better compared to the luxurious interiors of the palace; he was sure he'd go mad if he had to _live_ in there.

He heard a rustle behind him. Already unnerved by Kaelah's earlier attack, he spun round, eyes wide.

Kaelah was behind him.

She was smiling serenely. This unnerved Jalem even more.

"You should be in bed," he stuttered through dry lips.

"On a night like this?" Kaelah stepped closer.

"Every night's like this," Jalem pointed out. "We're under the sea, remember? In a cave."

"Ah, but the light's are dimmer than usual," purred Kaelah, stepping right up to him and winding his arms about her waist, reaching her own up to embrace his neck and shoulders. Her eyes seemed to glow for a moment, but when she looked up at him, her eyes were the same green they'd always been.

The lights are _dimmer_?" Jalem tried to pull away, now completely freaked out by Kaelah's attitude; but Kaelah held him tight. "That's _bad_, isn't it?"

Kaelah smiled slyly. "Yes, but it's very… _atmospheric_, don't you think?" Before Jalem could reply, she pulled his face towards hers and kissed him full on the mouth.

Jalem had kissed Kaelah before, but never like this. Instead of something tender between them, Kaelah seemed to be kissing him just for the sake of kissing. Again he tried to pull away, slightly hurt by this thought, and struggled even more when he felt something flowing into him. It tasted like water, but seemed to have a mind of its own. He made a noise of protest in his throat, and that was the last he knew.

DW

Susan guessed it was morning. In truth, all that had changed was the crystals were glowing brighter, albeit with the odd flicker. Beside her, Donna stirred.

"Morning," said Susan. "How're you feeling?"

"…Sick…" Donna bolted for the washroom. Susan winced at the retching sounds coming from within. She shrugged into her now dry clothes and sat down to wait.

"Her dreams had been full of sea life, as if she were scuba diving, despite never having done so in her life. A knock on the door woke her from her reverie.

"Morning!" said the Doctor, bouncing into the room with his usual energy. He stopped as he heard the sounds coming from the washroom. "Donna still ill?"

"Yeah…" Susan was silent for a moment. "What was all that about last night, anyway?"

"I heard you scream."

Susan looked genuinely surprised. "That's what you said last night. But I don't remember screaming, not even in a nightmare."

"That's why I-"

"Who's screaming?"

Donna had appeared in the doorway of the washroom, pale and leaning on the frame for support.

"You okay?" asked the concerned Doctor, jumping to catch her as she swayed. Donna managed a small shake of the head, not trusting herself to speak. The Doctor gripped her arm tighter as she swayed again and led her back to her bed, watching as she lay down. She fell asleep almost immediately. Susan watched him watch her for a moment, his brows furrowed. Then he beckoned and tiptoed out of the room.

DW

The park looked just the same as it had the day before. Petra, Jalem's dolphin, rose to greet them, before splashing back under the water.

"Which first, do you think, TARDIS or fire?"

"Fire?"

"Kaelah was trying to light a fire yesterday, and that was the last thing she remembered. I just want to have a wee nosy…"

"TARDIS first," said Susan suddenly. She looked as surprised at herself as the Doctor did. "I mean… unless you desperately want to have a look at the fire… I just think we should…go look at the TARDIS… first."

The Doctor nodded, and they swam across the pool to the TARDIS, with a little help from Petra.

Once inside, the Doctor strode straight through the control room, along a wide corridor and into what the Doctor claimed was a lab-cum-medical bay.

"You've really let things go," tutted Susan, de-tangling a bunch of wires and hanging them on their respective hooks.

"945 years old… whatcha gonna do?" the Doctor shrugged, donning his thick-rimmed glasses firmly onto his nose.

"You used to spank me for leaving my things in a mess like this."

"We don't _spank_ in this modern day and age. We _verbally discipline_ our wayward children."

"Which is another way of saying we let them get off Scot Free."

"Hmm… nice chap…" Susan rolled her eyes at her grandfather's back. "Pass me a petrie-dish, please." Susan did so. "Now," murmured the Doctor, pouring a little of Donna's blood onto the dish, "let's have a look…" He placed the sample under the microscope and peered in. "Funny…"

"Err… Grandfather?"

"Her blood cells are made of-"

"_Grandfather_-"

"_Apples and pears_?"

"That's my old toy microscope you're using."

"Oh." The Doctor reached for a real microscope. "Okay… that looks interesting… but not good."

"What is it?"

The Doctor looked up over his glasses.

"Donna's been drugged."

DW

In her room, Donna turned this way and that, mumbling a little; she was not sleeping well.

The door opened softly and blue feet padded inside. One pair stood by Donna's head, the other at her feet, and she was lifted between them off the bed, unable to retaliate at all in her drugged sleep, and carried away.

DW

_Power close. Must feed on Power soon. Power is everything. Need Power._

DW

The Doctor muttered as he rummaged through the cabinets in his lab-cum-medic bay. So far, he'd found some radiation pills, a couple of paracetemol tablets, three packets of sticking plasters, but no-

"Ah ha!" he yelled triumphantly, hitting his head off the top of the cabinet as he located the medicine which should stop the effects of the drug and make Donna feel a _lot_ better. He wriggled out of the cabinet and held up his prize for Susan to see. She smiled.

"The next trick is getting Donna to take it."

"Oh, I don't think that will be a problem. Trust me, she _really_ won't want to stay in her present condition."

"How bad is it?"

"She's probably feeling like Death at the moment."

Susan winced in sympathy. "Poor Donna."

"Yeah… what worries me is _how_ she ended up with some inside her in the first place." He was silent for a moment. "I'll give it to her once we get back. After I've sorted _you_ out."

"What!"

Susan backed away… something in her eyes had changed… they were _glowing_!

The Doctor lunged forward and rugby tackled her round the waist, pulling her to the floor. She tried to wriggle free but he held on determinedly. Suddenly, she gasped and went rigid.

A strange, clear substance poured from her mouth and started to inch away across the floor. The Doctor scrambled to his feet and trapped the whatever-it-was under a beaker, glad he'd never bothered to change the floor tiles in the lab to grills like the rest of the TARDIS when he changed the desktop theme. He slid a lid under and peered at his prize.

"Where did _you_ come from then, eh?"

DW

_Damn!_


	6. Chapter 5

Chapter 5

Susan looked at the thing with disgust.

"_That_ was _inside_ me?"

The Doctor frowned and held the jar protectively to himself. "Careful, you'll hurt his feelings!" He peered at the water-blob and grinned. "I think I'll call him… _Plato_."

"Why not Tolstoy, if you're going to randomly assign names to things?" asked Susan sarcastically.

"What's Tolstoy got to do with Atlantis? Besides, Tolstoy's taken."

"By who?"

"A bat."

"A bat…"

"Yup."

Susan rolled her eyes, then frowned and rubbed her temples. Then she gasped, her eyes wide.

"What's wrong?" asked the Doctor anxiously, setting Plato's jar down and stepping towards her.

"That thing attacked me!" exclaimed Susan, pointing at the jar and its contents. "I just remembered…" The Doctor clicked his fingers as if something had just occurred to him. He reached for Susan's temples.

"Can I come in?"

"If you must."

The Doctor sent his mind forth into Susan's. _Show me what it is you just remembered._ Susan's memories of the night before played out before him. _You're sure this was last night?_

_Yes._

_But this wasn't _in_ your mind last night._

_It just… came back to me, I guess._

"Hmm…" The Doctor opened his eyes and stepped back. "Remember what I said about someone not filing Kaelah's memories?"

"Yes…" Susan looked a little wary.

"It was just being sat on."

"Err… _what_?"

The Doctor launched into a realisation/imagery-frenzy. "Imagine your brain's an office, right, and each person's got a different job. So, you've got one poor person filing away all the things you see through your eyes. Obviously, you're almost always seeing something, so this wee busy person's a little frantic. Now imagine you've got a saboteur inside-"

"Plato?"

"Plato," the Doctor confirmed. "And he's taking over the office, like an "under new management" type of thing. But he's done it in an illegal or morally wrong way, and he doesn't want the Big Boss- that's you, by the way- to find out. So, he hides the data recording his entry by sitting on it, obscuring it from anyone looking in. And your poor image-filer will just think that he's been given slightly less paperwork to do for a change, which I'm sure he'd be thankful for."

Susan tried to banish the mental image she had of little people running around inside her head. It didn't quite work.

"So, are you suggesting that this is what happened to me and Kaelah?"

"Stating, more like. It might explain why she tried to attack Donna, too."

"But why-"

At that moment, Plato's jar crashed to the floor and he tried to flow away, but the Doctor caught him in a beaker and transferred him to another jar.

"He used momentum to make the jar topple over!" he exclaimed, examining the broken glass on the floor. "Clever!"

"Not necessarily a good thing," Susan pointed out, sweeping up the fragments with a brush and pan.

"True. Well, I think we'd better go show our little friend to the Council Elders, and give Donna that medicine. Allons-y!"

_Drat, drat and double drat!_

"Doctor!"

The Doctor stopped in his tracks and spun round to face the servant hurrying towards him.

"That's me."

"The Council requests your presence."

The Doctor raised his eyebrows at Susan, who shrugged. "You'd better go," she said. "I'll go give Donna the medicine." As the Doctor handed it over, Susan whispered, "Are you going to introduce them to our new friend?"

"Maybe. It depends on what they want me for." Susan nodded once and continued along to the bedroom, while the Doctor followed the servant to the Council Chamber.

The five Elders were seated as they had been the previous day: around a pool. Heram greeted him.

"Doctor! Thankyou for coming so quickly. I don't suppose you've seen Kaelah or Jalem at all today?"

"Nope, I haven't seen them since last night," replied the Doctor slowly, sure this wasn't the real reason the anxious looking Elders had summoned him. But, before he could ask, Susan burst into the chamber yelling, "Grandfather! Donna's gone!"

"That _was_ the next thing we were going to tell you," sighed Sani, shaking her head sadly. "One of the servants found a fine powder in the bottom of Donna's glass from last night. It appears she's been drugged."

"We know," said the Doctor darkly. "Susan was about to give her some medicine for it."

Donna rolled over on the hard surface and began to dry-heave. She felt terrible, and had nothing left to eject from her stomach. She could sense people walking around her, debating in low whispers, but her head didn't seem interested in understanding them. She caught the odd word, such as "human," "Time Lord," and "power," but it didn't make much sense. All she knew was that she'd fallen asleep in her and Susan's bedroom, and that she'd woken up here… wherever "here" was. _This has to be the worst bug I've ever had_, she thought.

Susan was amazed the Doctor had never worn someone's floor through, though it was probably just a matter of time; she'd have hated to have seen the bills he'd have got from irate people demanding he paid for the cost of a new carpet or something. Time-Travelling, while enjoyable, was only profitable in that it enriched your experiences.

She shook her head. It was a mark of how long she'd lived as a human, with everyday worries like bills, that she was now thinking of things as trivial as this.

"What would anyone want with Donna?" muttered the Doctor, completing one circuit of the room and beginning the next. "I mean, she's nice enough, but she's not special, she's not powerful, she's not connected, she's not clever, she's not important-"

"Woah, you are _so_ lucky Donna didn't hear you say that!" Susan grinned evilly. "She'd punch you in the face for that."

"She did, and she didn't."

"Bet she threatened to, though."

The Doctor continued his pacing. "What she _is_, though," he went on, pretending not to have heard his granddaughter's comment, "is connected to me, you and the TARDIS. Which is probably why old Plato here-" he patted his pocket where Plato's jar was "-had a shot at getting into your mind last night."

"But he did, though."

"Not as easily as he would have had if you'd been completely human."

The Council Elders looked completely at sea. Which they were.

"What _are_ you talking about, Doctor?" asked Ylea. "Who is this Plato?"

"A Greek philosopher who wrote a thing or two about Atlantis. He's also the namesake of this little blob here." He held up the jar for the Elders to see. "He decided to go brain-hopping into Susan last night, and we suspect one of his friends could be inside Kaelah."

"What would Susan or Kaelah have in their minds that this… _thing_ would want?" asked Forem nervously.

"I intend to find out," replied the Doctor, placing the jar on a table and opening the lid.


	7. Chapter 6

Chapter Six

The blob slowly inched its way out of the jar, before forming a small pool on the table.

"What do you want?" asked the Doctor, cutting to the chase.

_Power_. The voice seemed to surround them, echoing as if in an air pocket in an underwater cave.

"Interesting," murmured the Doctor, scratching his chin thoughtfully. "Telepathic communication. No wonder you got into Susan's mind so easily, telepathy's your first language!"

_Need Power._

"Alright, alright, you need power," said the Doctor. "What for?"

_Heart Failure._

"Heart Failure?" Susan was confused. "What does it mean by that?"

No one answered. The Doctor turned to look at the Elders, who'd all gone a very pale blue.

"Are you sure?" asked Sani fearfully.

_Need Power. Heart Failure. You have Power. Give us Power!_ Plato launched himself off the table and onto the Doctor. Susan yelled in dismay as she watched the blob force its way into the Doctor's eyes, nose, ears and mouth. The Doctor grimaced.

"Unpleasant," he groaned, his hands to his head.

"Plato's … inside you."

"I was aware of that, thanks," snapped the Doctor. His knees buckled and he sank to the floor, rubbing his temples. Susan knelt beside him.

"What's he up to?"

"Having a good poke at my defences, that's for sure," the Doctor said through gritted teeth. All of a sudden, he yelled. "Ah ha! _That's_ what he's after!"

"What?" asked Susan and the Elders all at once.

"_Power!_" exclaimed the Doctor triumphantly, jumping to his feet and clicking his fingers, as if he should have realised it all along.

The other exchanged glances.

"He… already told us that," said Jerom slowly.

"Yeah, but now I know what sort of power he means!"

"Which is…" prompted Susan after a few seconds.

"The same stuff that the TARDIS runs on."

"_Time_ energy?"

"Got it in one. You can tell you're one of _my_ descendants," smiled the Doctor. He swayed slightly. "Okay, um… Susan? Hold this, will you?" He handed her the empty jar and whipped his sonic screwdriver out of his pocket.

"What're you up to?" asked Susan warily.

"I have a little gate-crasher in my head and I've tried to ask him politely to leave, but he just won't listen and I am now obliged to use force." He pointed the sonic at his head. A high-pitched wail came from it, growing more and more intense, until everyone was wincing at the onslaught on his or her ears. Then they saw what looked like water dribbling from the Doctor's mouth, and Susan leapt forward to catch it in the jar, screwing on the lid, tight. The Doctor shuddered.

"Not pleasant, is it?" said Susan, handing him the jar back.

"Nope."

"Excuse me." Susan sighed before turning to look at Ylea; she really was getting sick of the woman.

"You used that thing on Kaelah yesterday," she said. "Why didn't it work like that then?"

"Higher frequency, this time. Of course, the minute I see her, I'll use it, but first we need to find her, and ascertain whether anyone else has been possessed."

"Well, I think you can tick both things off your list," said Susan, turning white.

"Why's that?"

"Kaelah and Jalem are here, that's why." She pointed at the doorway where the two stood, their eyes aglow.

DW

Donna was starting to feel a little better, though her head still throbbed nastily if she moved too quickly. She didn't know where she was, but she did know that the room she was in was small, cold, lit by one small, flickering crystal, and had about an inch of water on the floor. She was soaked from lying there.

_Great_, she thought. _I recover from one illness, only to find myself courting another._ She was alone now. The two pairs of feet she'd seen had left before she'd recovered enough to try and find out who their owners were. She knew they were Atlantean, but that was all.

Swaying and shivering slightly, Donna got to her feet and tried the door, just visible in the faint light. No luck. It was locked tight, and she couldn't see a keyhole to try and pick it with her hairpin.

A faint trickling reached her ears. At the same time, she became aware that the water was higher than it had been before. There was a leak somewhere.

The water was rising.

DW

The Doctor, Susan and the council members had all backed into a corner. Kaelah had run at the Doctor and knocked the sonic screwdriver out of his hand, crushing it beneath her foot. The Doctor had been rather upset about this, until Susan had whispered something in his ear and winked. Now he stood at the front of the little group huddled in the corner, his hands stuffed moodily in his pockets. Jalem and Kaelah were keeping them there with some rather sharp-looking spears. Behind them, a couple of blobs jiggled. The Doctor had very quickly stuffed Plato back in his pocket.

"Kaelah, Jalem, what is the meaning of this?" demanded Ylea angrily, stepping forward as far as she could without getting speared. The Doctor grabbed her arm and pulled her back.

"Don't. It's Kaelah and Jalem's bodies, but you're not addressing their minds. We have to tread carefully here. I doubt the blobs will have any qualms about disposing of them if they get in the way."

Ylea's skin turned even paler than before, and she stepped back.

"_Come with us_," said Kaelah's voice. Susan shivered involuntarily; she could have sworn she'd heard waves crashing behind each word. Then Jalem jabbed her in the arm when she didn't move.

"Ouch!" Her hand flew to her arm, and came away smeared with blood. She grasped the wound harder.

"Hey, hey, none of that!" cried the Doctor angrily, jumping back onto Heram's webbed foot as Kaelah turned her spear on him. There was a moment of jumbled confusion as the Doctor apologised profusely to everyone and everything, a blob or two got trodden on, Susan transferred something form her jeans pocket to her sleeve, and Heram cursed a lot in Atlantean- the TARDIS never seemed to translate those bits- then Jalem shouted, the sound of a tsunami behind his words.

"_Silence! You will follow us to the Heart_!"

The Elders all gasped.

"_The Heart of Atlantis?_"

DW

The water was higher, Donna was wetter, but she was still trapped. She'd yelled until she was blue in the face, and them some more, but to no avail. Wistfully, she wondered if it was possible to do a spot of instant evolution and get herself some gills, but she doubted it. She gave up shouting, partly because she wasn't sure how much oxygen she had left, but also because it was obvious there was no one nearby.

She splashed angrily, the water at her knees now. She decided the try and get the light crystal and have a closer look at it, for some reason she didn't know. As her fingers touched it, it flashed so brightly her eyes hurt. But in that brief moment of light, she'd seen an opening in the ceiling above. Time to get out.


	8. Chapter 7

Chapter Seven

They were led deeper and deeper beneath the palace. Somewhere in the back of her mind, Susan wondered why the enormous pressure that surely existed at this depth wasn't crushing them.

_Just be thankful it's _not, said the rational part of her mind.

She'd noticed that the decoration on the walls had become less and less elaborate the lower they got. She'd also noticed that the Elders' faces had grown less certain and more confused; obviously, they didn't come down here very often. After a while, they came to a dead end.

There didn't seem to be anything obviously different about this dead end- apart from the fact it was a dead end- and yet Susan felt there was something strange about this part of the palace. Then she realised what it was.

Unlike the rest of the palace, this part was lit by ordinary candles instead of crystals.

Jalem stepped forward and held out a crystal, it's blue light appearing green in the yellow light of the candles. He touched the wall with it, and it slid open.

"Nice," muttered the Doctor, making Susan jump; no one had spoken the whole journey down. "I wonder, what else can these crystals of yours do?"

"We use them for light and assistance in healing," Sani replied. "I've never seen them used as keys before."

Jalem and Kaelah prodded their captives forward, the blobs quivering around them.

They found themselves on a cliff edge in a huge cavern. Below them, water lapped against the rock they were clustered upon, and ahead, a huge crystal floated above the water. Actually, it reminded Susan of the LED "crystal" mobile that the care workers in her old home hung up in the games room every Christmas. Somehow, she didn't think the Atlanteans and water blobs would be too pleased with her comparison. Beside her, the Doctor whipped out his glasses and leaned forward to get a better look at the huge crystal glowing in the middle of the cavern. Susan automatically grabbed the back of his jacket to keep him from falling over the edge.

They became aware that the crystal was flickering, just like the light crystals in the palace above.

"The Heart of Atlantis."

Susan and the Doctor turned to look at the Elders. They were standing stock-still, transfixed. Their eyes shone brightly… _glowed_, in fact. They turned to face the Doctor and Susan.

"Err… Grandfather…"

"I know."

DW

Donna braced her legs and back in the pipe she was climbing and pushed her hair out of her face. Holding it there with one hand, she dug around in her pockets with the other in search of a hair bobble or something, but there was nothing except the crystal she'd pinched from her cell. Sighing, she forced herself further upwards-

-and banged her head. Rubbing it, she pulled out the crystal and held it up so its blue light illuminated the pipe around her. She'd reached a bend in the pipe; it was now horizontal.

_At least it'll be easier going._

She crawled along the dark tunnel, a section gave way, and she fell through.

DW

The Doctor didn't know what had hit him, but from the expression on Susan's face, he could guess.

"Donna?" he croaked, wincing.

"Sorry…" He felt her get up, and got to his feet, holding his bruised back.

"No problem." He peered at her sopping wet hair and clothes and grinned. "Glad to see you're feeling better."

"Grandfather!"

He spun round, just in time to see a water blob heading straight for him. He ducked, and it sailed right over his head and into the water. The other ones followed, including the ones inside Jalem and Kaelah, and the glow left the Elders' eyes. In the Doctor's pocket, Plato banged ineffectually against his jar.

The group gazed in fear and wonder as the water rose, gathering itself around the crystal, forming a shape around it.

Forming the shape of a man.

He was as tall as the cavern, and composed entirely of the water that had once filled the cavern. Where the heart should have been in his transparent body, the crystal glowed eerily, the light casting rainbow colours over the spectators.

_I am Atlantis. I am the Sea_.


	9. Chapter 8

Chapter 8

As one, the Atlantean Elders knelt before the huge figure, leaving the Doctor, Susan and Donna standing awkwardly. The Doctor let Plato out of his jar and watched the little blob flow into the figure.

The figure stepped forwards, shadows dancing across the cavern as it moved. The crystal-heart flickered, and it stopped for a moment, what could be a frown passing over its face.

_It's in pain_, Donna realised.

_Power_, said the echoing voice of the water person.

The Doctor stepped forward.

"Yes, yes, we _know_ you're after power," he began exasperatedly, but was stopped by a glare from Jerom.

"Show some respect for Atlantis," the Elder hissed.

"Sorry, never been one for respectfulness myself. Rude and not ginger, that's me. Besides, surely I have a right to be at least a _bit_ rude, considering two of your servants have been possessed, my friend's been drugged, my granddaughter's had her mind invaded and I've had a gate-crasher in my head. Did I miss anything? Oh, yeah, we've been frog-marched by a bunch of blobs to this under-sea cavern."

"I was _drugged_?" Donna was appalled.

"We were supposed to give you this to make you feel better," said Susan, holding up the medicine, "but I'd guess you don't need it now."

"Anyway…" said the Doctor loudly, drawing their attention back to him. "I'd like to know a little more about this "power" you're after."

_Your Power_.

"You mean, the time energy on which my TARDIS runs? And why would you want that particular kind? Why not solar? You don't get much sun here, of course… same goes for wind power… what about wave power? You've got the whole _sea_ at your disposal, after all-"

_Need _your_ Power. Heart failure._

This repetition was getting frustrating. "Why does this "heart failure" mean you need time energy?" asked Susan.

"Because it's dying," said a voice behind them. They turned to look at Kaelah, who was staring at Atlantis with awestruck eyes. "I felt it when he possessed me. You need this power to keep Atlantis alive, don't you?"

_I am Atlantis._

"You're Atlantis!" The Doctor clapped his hands together, putting two-and-two together as only he knew how. He began his excited whirling and jumping that Donna had come to expect. Again, Susan grabbed a hold of his jacket to keep him from tumbling over the edge of the cliff. He looked at her indignantly and she raised her eyebrows at him, letting him go. He continued his realisation moment, albeit in a slightly more dignified manner.

"You are what's keeping this whole civilisation alive! That crystal is the Heart of the Sea, the Heart of Atlantis- _your_ heart! It's not just a figure of speech or some fancy title; it's the honest truth. Oh, I love it when people tell the truth! But you're dying… that's why the light crystals keep flickering."

_Need… Power._

"You do, you do," agreed the Doctor, his head bobbing like a Churchill dog's.

"Then give it to him!" yelled Jerom angrily, getting stiffly to his feet. He glowered at the Doctor, and the other Elders did the same. "He says you have the power he needs, so surely it's a simple matter of giving it to him."

"It's not that simple," sighed the Doctor, reversing his Churchill impression.

"Why isn't it simple?" cried Sani, close to hysterics.

"He wants time energy, but alone it won't help. It'll simply weaken, and we probably won't be here to save him again," explained Susan gently, aware that the Atlanteans outnumbered them eight to three, if you counted their god or whatever it was, and could easily keep them in Atlantis if the idea occurred to them.

The Atlanteans looked stunned. They were facing the death of their entire civilisation, and their only hope wasn't all that hopeful.

"However, we _can_ figure out a way to help, and the first thing to do is get the TARDIS, so, if you'll excuse me for a moment-"

_Stop!_

Atlantis reached out and grabbed the Doctor, lifting him from the ledge.

_You will wait here. The women will get the source._

"Absolutely, I totally agree. _Brilliant_ idea," gasped the Doctor, wriggling ineffectually against the surprisingly solid fingers. "We can all have cake while we wait. Or chips! Everyone loves chips! With a nice bit of battered fish… or perhaps not…"

Susan and Donna backed warily out of the cavern and had managed to get to the main corridor before they began to snort with suppressed giggles.

DW

The Atlanteans jumped at the sounds of alien engines wailing, then their jaws dropped and they cowered against the rough walls as a huge blue box appeared beside them. The Doctor yelled triumphantly, still held in Atlantis' fist.

Donna emerged shakily, followed by an indignant Susan.

"Well, _I'm_ sorry if I'm out of practice. Being abandoned by your grandfather for over forty years doesn't exactly enable you to practice your time and space travelling skills!"

"And I thought the _Doctor's_ driving was bad-"

"Oi!"

_Give me Power,_ roared Atlantis.

"Say please." The Doctor immediately regretted his words- a regular occurrence, he noted- since Atlantis tightened his grip.

"Let him go!"

_Need Power._

"We can't give you power unless you let him go!"

_Give me Power!_

Susan pulled out a slim tube from her sleeve and pointed it at Atlantis. The tip began to glow blue.

"Let. Him. Go," she said slowly and clearly.

Atlantis seemed to grumble, like waves on a beach, then set the Doctor down beside his beloved TARDIS.

"Okay, now I'm completely convinced that you're his granddaughter," said Donna.

The Doctor massaged his ribs. "Okay Dokey, let's get this show on the road!" he said in his best American drawl. Susan rolled her eyes.


	10. Chapter 9

Chapter Nine

Donna leaned against the TARDIS' doorframe, gazing up in fascination as the giant let a droplet of itself fall into the Doctor's waiting jam jar.

"Plato, hello again, mate!" he said delightedly, a huge grin on his face. He looked up from his prize to examine the Atlanteans. "I need a volunteer."

"What for?" Jerom's voice was laced with suspicion.

"Oh, knowledge, assistance, a spot of blood…" said the Doctor airily.

"_Blood?_" The Atlanteans backed away a little. Then Kaelah stepped forward.

"I'll do it. It's my fault, after all-"

"Of course it isn't," retorted Susan, taking her by the elbow and leading her inside the TARDIS. Donna heard the girl gasp as she saw the huge interior and smiled. Her own reaction had been a little different, having seen the inside first. Emerging after the Doctor landed in London, _that_ was when she got the it's-bigger-on-the-inside shock.

The Doctor already had his head stuck in his magic lab cupboard, and vaguely Donna wondered if Susan had stuck some Doctor-treats or something in there. He began throwing random things out of it again.

"No… not this… not- how did _that_ get in here?"

Donna narrowly dodged a flying rubber duck and sat beside Kaelah. The girl looked very out of place in the green and gold interior with her blue skin and white hair. She also looked rather scared.

"You okay?" she asked kindly as Susan went to help the Doctor find whatever it was he was looking for. Kaelah nodded numbly.

"Is it always this weird, your life?"

"Since I met him, yeah," admitted Donna. "But you think it's weird for _me_, just wait 'till you hear _Susan's_ story. She's a lot older than she looks, and she was _brought up_ with this kind of lifestyle."

"Still lookin' good, though," said Susan as she crossed the lab to another cabinet. "A blow-up hammer, Grandfather?" she added in a bemused voice, pulling out the item in question with some difficulty.

"Must've been the Master," muttered the Doctor, still rummaging in the cupboard with his bum sticking in the air. "My we've had some cowboys in here… oh, _yes_!" He retreated from the cupboard, clutching a magnifying glass. He held it up to his eye, enlarging it bizarrely. "Perfect."

He scrambled to his feet and grinned, holding out a hand. "Microscope." Susan handed him one. He eyed it suspiciously.

"It's real, don't worry."

"He smiled even wider and put Plato and his jam jar underneath. Making lots of oohing and ahhing and mmm-hmming sounds, he scribbled in a notebook, waved his sonic screwdriver at his specimen, made more noises and scribbled some more in his notebook.

"Okay, Kaelah, I need some blood now."

Kaelah shrank back a little.

"Oh, you'll be fine, I only want a little." He took a syringe from his first-aid kit and told Kaelah to roll up the sleeve of her tunic. "Look away if you want, it always helped Susan."

"No, that was _you_," said Susan, her arms folded.

The Doctor ignored this and proceeded to take some of Kaelah's blood. It was a reddish-purple colour.

"Interesting…" Sticking a small plaster on the girl's arm, he put his new sample under his microscope and began to scribble more notes, waving his screwdriver as he did so. After a while, he straightened up.

"Any ideas, then?" asked Donna.

"Plenty," replied the Doctor. "Doesn't necessarily mean they're _good_ ones, mind, though, being me, they probably are."

"Modest as ever," muttered Susan

"Of course."

"Are they normally like this?" whispered Kaelah to Donna. Donna whistled softly.

"You have no idea." Then she looked up at the Doctor. "So, what are we gonna do?"

The Doctor was back in his cupboard. He emerged to reply. "We should be able to use the heart of the TARDIS to re-charge Atlantis' batteries, so to speak. Of course, it won't be the energy in its _purest_ form-"

"Why not?"

"Oh, just the little snag that no living being in the Universe could handle such power for very long, not even a Time Lord." He was quiet for a moment, staring into the distance. Susan and Kaelah looked at him curiously, but Donna just sighed quietly to herself. She'd be willing to bet anything that he was thinking about Rose.

"_Anyway_," he continued after a moment as if nothing had happened, sticking his head back in the cupboard. Somehow, he managed to inject those three syllables with bundles of energy and enthusiasm. "We can still give Atlantis plenty of power. Renewable, too. Can't beat some renewable power."

"And where's the "renewable" bit going to come from?" asked Susan, who had a feeling she already knew.

"Me, of course!" beamed the Doctor, proving Susan right. "If I can get myself some of the regenerative properties in _my_ blood, I _should_ be able to create a similar effect in the energy bar I'm giving Atlantis-"

"Time Lords only get twelve shots at regeneration," Susan pointed out.

"True, but mixed with Time Energy…"

Susan looked at him through narrowed eyes for a moment.

"You're making this up as you go along, aren't you?" she said eventually.

The Doctor gave her his most winning smile. "Improvisation, it's what I do best!"

Donna wondered if Susan's eyes always rolled, and she just hadn't noticed before.

_Doctor!_

"Yeah, just a sec!" yelled the Doctor, somehow squeezing more of himself into the cupboard. Well, it _was_ a TARDIS cupboard.

Heart… Failure…

"Just hang on!"

"Doctor!" It was Sani's voice, coming from the control room. Donna and Susan ran out to meet her.

"It's Jerom," she said breathlessly. "He just… _collapsed_, he's…" she swallowed. "He'd _dead_!"


	11. Chapter 10

Chapter Ten

Susan was out of the TARDIS and on her knees beside Jerom in a flash. Death was something she'd faced a lot in her lifetime- a side-effect of travelling with the Doctor and being a nurse- but she still found it a terrible experience to check a body for life signs only to find none.

She checked his pulse and breathing just to be sure. Nothing. She sighed and rocked back on her heels. "What happened?"

"He just keeled over!" sobbed Ylea. "Not a word, not a sound!"

"Nothing else?"

"He seemed to glow for a moment," admitted Herom. "But whatever the light was, it faded." Suddenly, he fell too. His eyes glowed, and he looked incredibly calm. Susan watched in horror as the light faded. In the corner of her eye, she sensed something float past her. She followed it, and what her gaze fixed on made her gasp as she put two and two together, to arrive at an accurate, correct, and severely unwanted four.

"Into the TARDIS, everyone, _now_!"

"We won't fit in there," said Jalem doubtfully.

"Trust me, we will," Susan assured him, shoving him through the door. "_MOVE!_"

They did as they were told, and Susan dashed back into the lab, where the Doctor was bent over what looked like a metal pipe with levers sticking out.

"Grandfather!"

"Just a second, Susan, I'm almost done." He tweaked it a little. "There!"

"Grandfather, Jerom and Herom are _dead_!"

The Doctor looked up, his eyes wide. He grabbed his pipe and ran out of the lab, Susan right behind him. In the control room, Donna had shepherded the remaining Elders into the seat beside the console. Sani had her arm round the still-sobbing Ylea.

"What exactly happened?" asked the Doctor urgently, waving for everyone to step back from the console.

"He just sort of… keeled over…" began Sani shakily, "and there was this light-"

"I think Atlantis took their life energy," said Susan flatly. The Doctor nodded as if this had been what he'd expected, which it probably was.

"It looks like he's picking you off by age order. Who's next?"

Ylea gasped and sobbed even harder.

"I'd imagine that means you, then," murmured the Doctor, peering out the door. "Oi, Atlantis!" he yelled. "Stand over there, please!" Without waiting to see if the giant had obliged, the Doctor dashed back to the console and hooked his fingers under the control panel. Then he paused and looked round at the assembled humans, Atlanteans and human/Time Lord hybrids and bit his lip. Susan looked at him questioningly.

"Donna, could you take this lot somewhere else, please, like the lab. Susan, stay here." Donna looked puzzled, but did as she was told. As soon as they were gone, the Doctor handed his pipe to Susan.

"As soon as I lift this panel," he instructed quickly, "shove this pipe in so it's pointing out the door, and whatever you do, _don't look inside_."

Susan nodded and did as she was told. She looked away, but not before she'd caught a glimpse of a blinding white light- the Heart of the TARDIS.

The Doctor flicked various levers on his modified pipe.

"They're connected to filters based on the blood samples," he explained in a rush, wincing at the bright light glaring through the pipe and into the waiting Atlantis. "Like I said before, I can't give him the energy in its purest form, but I _can_ filter it and give it a few artificial flavours and vitamins…"

Susan watched in fascination as Atlantis became a huge figure seemingly composed of light, then watched the light shrink, until his Heart was glowing like a sun. The Doctor watched with wide eyes; Susan could see the light reflected in them.

The spectacle lasted only a few moments; bent by Atlantis' watery body, the light cast rainbow colours and rippling patterns over the cavern. Then the water fell from the Heart with a great splash, leaving the crystal floating in the centre. The Doctor clapped.

"Oh, that was _brilliant_!" He yanked the pipe from the console, a huge grin plastered on his face.

"You want to explain it all?"

The Doctor took a deep breath: "Well, since the energy from the Time Vortex is too much for Atlantis, I created filters based on the blood samples from Kaelah and myself and the sample from Plato, then it was a simple matter for me to fit them into this pipe and calibrate the-"

"Never mind," interrupted Susan, sighing. It had been too long since she'd listened to a science lecture, and a lot of it was going over her head now. "Anyway, will we call the others back?"

"Yeah, go on, then."

Donna looked a little indignant as she emerged from the lab.

"Is it over?" asked Sani timidly.

"Nope," replied the Doctor cheerfully. "It's just beginning." He waved expansively at the brightly-lit cavern. "Check it out, Sani, a new Atlantis. A new life for everyone upstairs.

The group gazed in awe for a moment. Then Ylea broke the silence.

"What about Herom and Jerom? What will we tell everyone?"

The Doctor turned to look at her, his face serious.

"The truth."


	12. Epilogue

Epilogue

"I wish there was some way we could repay you."

Susan glanced at the Doctor. He had his back to them, staring out across the city.

They had parked the TARDIS on a balcony of the Palace. Susan shook her head.

"Don't say that," she warned the Atlantean quietly. Sani frowned but didn't ask.

"Five minutes!" cried out the Doctor suddenly, striding into the TARDIS. Donna appeared at Susan's arm.

"Not one for short goodbyes, is he?" she muttered sarcastically. Susan didn't reply. She hated long goodbyes too. It was difficult to leave people having made friends with them, knowing you had several lifetimes more of it to come.

"I wish you all the best, Sani."

"And I you, Susan and Donna. And thankyou."

The three women hugged, just once, then Susan and Donna stepped into the TARDIS. Sani stood on the balcony, watching the TARDIS as it faded away into Time and Space.

"So, where now, Doctor?" Donna frowned. "Doctor!" The Doctor jumped.

"2012 Olympics!" Howzat? I was there, you know. Torchbearer!" The Doctor ran round the control room waving an imaginary torch above his head. Suddenly he stopped short and shuddered.

"Something wrong?" enquired Susan with a bemused look on her face. The Doctor grimaced and slipped a hand under his shirt. He withdrew what looked like a clear blob.

"Plato! I'd forgotten about you!"


End file.
